Single or multi-strand cable window lifters are known, particularly for motor vehicles, which comprise a drive unit which has a manual or motorized drive and a drive drum, a guide rail or several guide rails for one or more drivers, which are connected to a window pane, and a cable wound round the drive drum, and several cable deflection pulleys. The cable deflection pulleys have a guide or bearing groove in which the cable is guided and deflected.
FIG. 1 shows, as an example, a single-strand cable window lifter for raising and lowering a window pane 7 which is set in a driver 6. The driver 6 is connected to a cable 4 and is mounted displaceable on a guide rail 5. The cable 4 is wound round a cable drum 3 of a drive unit 1, which in the illustrated embodiment has an electric motor 2 as the drive element. Cable deflection pulleys 8, 9 are mounted at the ends of the guide rail 5 and deflect the cable 4, which is guided in the area of the guide rail 5 parallel to the guide rail 5, towards the cable drum 3 where the cable 4 is wound one or more times round the cable drum 3 and is connected to same. Through rotation of the cable drum 3 in the one or other rotary direction the driver 6 is raised or lowered together with the window pane 7 on the guide rail 5.
FIG. 2 shows in an enlarged individual representation, the cable deflection pulley 8 which is mounted at the upper end of the guide rail 5 according to FIG. 1. The cable deflection pulley 8 has an axial bore 80 which is pushed onto an axle which is provided with the guide rail 5 or with a fastening element connected to the guide rail 5. Several webs 81 connect the wall of the axial bore 80 to the wall of a guide or bearing groove 82 in which the cable 4 is guided and deflected.
The cable 4 is connected in frictional engagement to the cable drum 3 or to the ends of the cable drum through positive locking elements. In the `relaxed` state of the cable window lifter, the cable has a cable slack which can lead to undefined motion states of the driver 6, and thus, of the window pane 7, as well as to considerable noise and accelerated material fatigue, and ultimately, to system failure. To remove the cable slack, the cable is tautened and is pushed in this tautened state, that is with a corresponding cable length or through the arrangement of spring elements, onto the cable deflection pulleys 8, 9 according to FIG. 1.
In order to facilitate the insertion of the cable 4 into the guide grooves of the cable deflection pulleys 8, 9 according to FIG. 1, it is known to provide at least one of the cable deflection pulleys with a notch 83 according to FIG. 2 into which the cable 4 is inserted and introduced into the guide groove 82 through further rotation of the cable guide pulley 8.
Through the sharp angling of the cable 4 during insertion into the notch 83, however, there is the danger of damage to the cable through it becoming spliced or bent. Because this cable area is then always moved in the deflection area of the cable deflection pulley there is also the risk of the initially damaged cable tearing in this area.
Furthermore there is the drawback that the cable is fitted in an unergonomic sequence of movements by rotating the wrist with a simultaneously high amount of force which leads to premature fatigue and damage to the wrist of the fitter.
Furthermore this method of fitting the cable is linked with a time-consuming assembly since first the notch 83 has to be brought into a favorable position for assembly and then the cable has to be inserted into the guide groove while applying a high amount of force.